Observations concerning the functional status of the corpus luteum and the placenta around parturition in the cow

Hoffman, Barbara; Wagner, Waldemar; Hixon, J. E.; Bahr, Janice M.

doi:10.1016/0378-4320(79)90051-4

Cited by 89 publications

(60 citation statements)

References 11 publications

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“…'s secretory activity is enhanced in late gestation when monkey chorionic gonadotropin (mCG) is undetectable in the peripheral plasma [35]. However, it still remains to be verified how these observations can be extrapolated to other species, as there is a reduction in the peripheral LH in late gestation in the cow [32] but fetectomy has no significant effect on maternal plasma progesterone levels [7] and so far data on the effect of fetal sex in this species are conflicting [10,36]. Other luteotrophic factors have been identified in the cow but their in vivo effect has yet to be clearly delineated [37,38].…”

Section: Discussionmentioning

confidence: 96%

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Progesterone Concentration throughout Gestation in Cows with Singleton and Twin Pregnancies.

Patel¹,

Takahashi²,

Hirako³

et al. 1995

J. Reprod. Dev.

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Section: Discussionmentioning

confidence: 96%

“…, placenta [3,4] and progesterone sequestered in adipose tissue [7] have all been suggested to be this source of progesterone.…”

mentioning

confidence: 99%

Progesterone Concentration throughout Gestation in Cows with Singleton and Twin Pregnancies.

Patel¹,

Takahashi²,

Hirako³

et al. 1995

J. Reprod. Dev.

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“…Conjugated oestrogens also exceed that of free oestrogens; however, oestradiol-17a-sulphate, but not oestronesulphate, is the major oestrogen in foetal blood (Hoffmann et al, 1976). It was suggested that oestrone (free and conjugated), which is produced and released from the cotyledons, must be reduced into oestradiol-17a when entering the foetal compartment (Hoffmann et al, 1979). At around parturition, the concentrations of oestradiol and oestrone in foetal vena cava plasma are only about 20 pg/ml (Peterson et al, 1975).…”

Section: Concentrations Of Progesterone and Oestrogens In Foetal Bloodmentioning

confidence: 99%

Multilevel regulation of steroid synthesis and metabolism in the bovine placenta

Nguyen

Conley

Soboleva

et al. 2012

Molecular Reproduction Devel

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SUMMARYSteroid hormones play critical roles in almost all physiological processes in male and female reproduction. In a normal pregnancy, the concentrations of steroid hormones in maternal and foetal blood vary with gestation in response to changing needs. The placenta plays a central role in producing the appropriate steroids to support the pregnancy by coordinating its own steroidogenic activity with that of the corpus luteum and responding to foetal signals. Although much is known about the steroidogenic potential of the bovine placenta, far less is known about how the placenta integrates the synthesis of steroids with their subsequent metabolism and clearance to achieve appropriate local and peripheral concentrations of steroids in maternal and foetal blood at each stage of gestation. This review focuses on the current knowledge of the temporal and spatial regulation and compartmentalization of the biochemical pathways by which potent steroid hormones are synthesized and metabolized in the bovine placenta. The aim is to increase our understanding of how the balance of synthesis and metabolism determines placental steroid output as it changes with development and differentiation, and how this is regulated in response to the variations in the foetal signals and luteal secretory activity. The review highlights knowledge gaps and suggests that mathematical modelling can help understand the effect of different levels of regulation on the steroidogenic output of an organ, such as the bovine placenta.

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“…Antibodies against estrone (anti-estrone-6-carboxymethyloxime (CMO)-BSA rabbit serum) and estradiol-17β (anti-estradiol-17β-6-CMO-BSA rabbit serum) were purchased from Cosmo Bio (Tokyo, Japan). The concentration of estrone sulfate was measured using a competitive radioimmunoassay with [6, H(N)]-estrone sulfate (PerkinElmer Life Sciences, Boston, USA) and a specific antibody (anti-estrone-3-sulfate-6-CMO-BSA rabbit serum (Lot 465) 11 ) with 0.2 mL of the reconstituted solution of 40% methanol eluent. Assay procedures of all the estrogens were previously described in detail 5 .…”

Section: Radioimmunoassaymentioning

confidence: 99%

“…It plays an essential role in the maintenance of pregnancy 19 and the initiation of parturition 6,18 .…”

Section: Introductionmentioning

confidence: 99%

Changes in Plasma Estrogen Concentrations during the First Trimester of Gestation in Dairy Cows: Comparison with the Origin of Embryos and Fetal Number

Hirako

Takahashi

et al. 2003

JARQ

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The objectives of this study were to determine the profiles of plasma estrogen concentrations during the first trimester of gestation and to correlate them with the origin of the embryos and fetal number. Pregnancies were induced either by artificial insemination (AI) on the day of estrus (day 0) or by transfer of 1 or 2 blastocysts produced in vitro (IVF-ET) on day 7. Five singleton-bearing cows impregnated by AI, and 6 singleton and 6 twin pregnancies induced by IVF-ET were used in the experiment. Blood was collected by jugular venipuncture at 2 to 5-day intervals until day 100. The concentrations of plasma estrone, estradiol-17β and estrone sulfate were measured by using a radioimmunoassay. Concentrations of all the estrogens fluctuated at low levels until day 50 in all the groups. Thereafter, the concentration of estrone sulfate gradually increased, whereas those of estrone and estradiol-17β remained at basal levels until day 80. The concentration of estrone sulfate after day 50 was affected by the day of gestation and the number of fetuses. After day 80, the concentration of estrone sulfate increased drastically, coinciding with the increases in the estrone and estradiol-17β concentrations. The rate of increase in the concentration of estrone sulfate during days 80 to 100 was the highest among all the estrogens. In the singleton pregnancies, the concentrations of estrone and estrone sulfate between days 80 and 100 were higher in the artificially inseminated cows than in the IVF-ET cows. In the pregnancies induced by IVF-ET, estrone sulfate levels were higher in the twin-bearing cows than in the singleton-bearing cows during days 50 to 80 and 80 to 100. These results suggest that the concentrations of estrogens in bovine peripheral blood plasma could be applied for monitoring fetoplacental development in the first trimester of gestation.Discipline: Animal industry Additional key words: estradiol-17β, estrone, estrone sulfate, in vitro fertilization and multiple pregnancies JARQ 37 (3), 195 -200 (2003) http://www.jircas.affrc.go.jp Present address:

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Observations concerning the functional status of the corpus luteum and the placenta around parturition in the cow

Cited by 89 publications

References 11 publications

Progesterone Concentration throughout Gestation in Cows with Singleton and Twin Pregnancies.

Progesterone Concentration throughout Gestation in Cows with Singleton and Twin Pregnancies.

Multilevel regulation of steroid synthesis and metabolism in the bovine placenta

Changes in Plasma Estrogen Concentrations during the First Trimester of Gestation in Dairy Cows: Comparison with the Origin of Embryos and Fetal Number

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